Field of the Invention:
The present invention relates to a method of and an apparatus for air-conditioning individual spaces in a central heat source system for cooling or heating individual spaces by means of air-conditioners respectively disposed therein.
Description of the Prior Art:
As one method of air-conditioning using a conventional central heat source system, a method of air-conditioning such as the one shown in FIG. 3 is known. In the drawing, in a cold and hot water generator 5, approx. 7.degree.C. cold water is created as a heat medium at the time of cooling, and 50 -60.degree.C. warm water is created at the time of heating. Such water is supplied to individual rooms which constitute spaces to be air-conditioned, by means of a pump 6 via the piping 7. Air-conditioners 8A, 8B, 8C, and 8D, which are formed as heat exchangers and serve as room units, at least one for each room, are installed in the respective rooms. The room temperature is controlled by effecting cooling by using cold water supplied through the piping 7 or heating by using warm water supplied through the piping 7. Subsequently, cold water used in cooling is warmed, or warm water used in heating is cooled and returned to the cold and warm water generator 5, where the temperature of the water is controlled again to a predetermined level.
In such a conventional method of air-conditioning based on the central heat source system, the cold and warm water generator 5 is capable of generating either one of approx. 7-C. cold water or 50-60.degree.C. warm water at a time. Therefore, if, for instance, cooling and heating are required simultaneously for the space in which the room unit 8A is installed and for the space in which the room unit 8B is installed, respectively, it has not been possible to meet the requirements simultaneously. However, in the case of air-conditioning a building, there are cases where cooling is required for a sunny zone which faces the south, while heating is required in a zone which faces the north and does not admit much sunshine. In addition, in an electronic computer room, there are cases where cooling is required even during the winter season since the amount of heat generated therein is large. Thus, in recent years there has been an increasing number of cases where cooling and heating are required simultaneously within the same building. With respect to the form of air-conditioning load in which cooling and heating are required simultaneously for a certain zone and for another zone, respectively, the above-described conventional method of air-conditioning based on the central heat source system has had the problem that it cannot cope since the cold and warm water generator is able to produce either cold water or warm water at a time. In addition, it has been necessary to adopt an individual air-conditioning system in which independent air-conditioners are arranged in individual spaces to be air-conditioned. In the case of this individual air-conditioning system, since a heat source is provided for each air-conditioner, there has been the problem that the equipment costs become high and the loss of thermal energy is large.